Rotary jar



Feb. 22, 1927.

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J. IA. KAMMERDINER" ROTARYYJAR.

original Filed'npril 13, 1925 ATTORNEYS.

Patented Feb. 22, 1.927.

UNITED STATES PATENT oFFlcE.

v JAMES ALLEN xAMMEnnINEn, or Los ANGELES, CALIFORNIA.

ROTARY JAR.

Application led 4April 13', 1925, Serial No. 22,584. Renewed November 22, 1926.

This invention relates to a rotary .jar for use in well drilling apparatus, and 1s especially useful in fishing jobs wherein lost tools, articles, or parts are`stuckin the hole and must be dislodged. I have disclosed a device of this character in United States Letters Patent for rotary jar reissued to me February 12, 1924, No. 15,760, and Letters Patent granted to me March 10, 1925, No. 1,529,544.

vJars of this type comprising relatively rotatable hammer and anvil sections have been set by rotating the-sections. Theyv are then released byV rotation thereof inthe opposite direction. 'Safety joints are commonly placed in the string of pipe or rods supporting the jar, and are easily unscrewed by turning the string of pipe in a direction opposite to that or tightening the threads. Setting of the jar must be effected by turning in one direction. and tripping must be etected by turning in the opposite direction. If this is done by turning the string from above, there is a tendency to open the string at the safety joints. It is the primary object of this invention to provide a jar having means toautomatically set the same by `pressure thereon. It; is another object of this invention to provide means which will he' effective in assisting the impact blow of the jar upon tripping.

These objects together with other objects and corresponding accomplishments are obtained by means of the embodiment of my invention illustrated in the accompanying drawing, in which:

Fig. 1 is an axial section: through a. 'jar in expanded position; Fig. 2 is a similar View of, the jar in contracted position; Fig. 3 is a section as seen on the line 3--3 ot Fig. 1; Fig. 4 is a section as seen on the line 4-4 of Fig. 1; andFig. 5 is a section as seen on 'the line 5-5 of Fig. 1.

Referring more particularly to the drawing, a cylindrical body or cage 6 is provided with a tapered threaded pin 7 at the upper end, and has a bore 8 extending therethrough. The body is internally threaded at, the lower end, and mounted therein is, a closure member 9 forming an anvil. The upper lend of the bore is reduced in diameter to form a plunger chamber 10; Within the bore is a mutilated thread 11 formed of two diametrically opposed portions, each occupying approximately -one` quarter 'of the periphery; Fillets 12.' `ormsstops for the threads'.

Disposed Within the cage is a hammer comprising a cylindrical head 13 adapted to engage the anvil 9. The hammer head is provided with a tubular mandrel 14 which slidably extends through the borein the anvil. -This mandrelis provided at its lower end with a threaded pin 15 for attaching any suitable device thereto, such as a string of pipe. A shank 16 is extended above the head and is provided with threads 17 for meshing with the corresponding threads on the cage. These threads form in eiect shoulders which are inclined to the' axis of the cage and may also be provided with tillets to form stops. The shank. is extended upwardly to form a tubular plunger 19 slidingly mounted in the chamber 10. At the .upper end of theY plunger are cup leathers 20. The hammer member has a 'cylindrical bore extending therethrough so ing the tool in a circulation line. liountedVV overthe shank 14 is a left hand compression spring 21. One end of the compression spring is mounted in the plug 9 and held in position by a set screw 22. The other end rests in a recess in the pin 15. The constructionis such that if the shank parted, the spring will remain with the anvil section and may be moved from the hole.

The jar is placed in a string of tubing or pipe, a fishing tool depending from the bottom of the string. Upon getting a grip upon the fish the jar is telescoped by lowering the string. This causes the spring 21 to be compressed with a consequent rotation. The

yrotation of the sections causes the segments of the thread on the hammer shank to slide between the sgements of the thread on the cage. The fillets prevent the hammer from riding out of mesh with the cage thread, and furthermore, in this position continuous 'rotation of the string may be elected. The enlargement of the chamber on one side of the hammer head is counter-acted byfthereduction on the other side.

Projecting laterally from the shank are lugs These lugs are diametrically opposite to one another and are positioned in line with the months of the thread on the shank so that as the shank is moved upwardly, the

, them into engagement.

hammer cannot be turned until the threads on the hammer and cage register, whereupon the lugs ride over the edges of the thread 11, and the parts are turned so that'they mesh. Upon telescoping of the jar from the osition shown in Fig. l to that shown in `ig. 2 there is a torsional force exerted tendin to rotate the sections relative to one anot er. As soon as the threads register, they are free to turn, and the splring action moves aving laced the threads in mesh, a pull is exerte upon the string, and after the pro er tension has been reached, the jar is turne or rotated. Rotation of the two parts causes the segments-of the threads to-ride out of mesh and trip, whereupon the hammer strikes the` anvil causing a jar or impact u Wardly. Iron or metal pipe or tubing use in oil Well Work has elasticity which is very appreciable in a string of the length commonly used in wells. This elasticity assists in creating the jarring effect upon release of the hammer# What I claim is:

1. A rotary jar for use in Well drilling `ment of the members is prevented, but when. Iout of engagement longitudinal movementof said members is permitted, and means operated by closure movement of said members to turn said shoulders into en agement.

2. A rotary jar for use in wel drilling comprising a rotary hammer member and 1. rotary anvil member telescopically connected, each of the members having trip shoulders, said shoulders being interrupted to permit the passage of the shoulders on the ammer members past the-shoulders on the hammer member past the shoulders on the anvil member, and when said shoulders are in engagement further longitudinal movement of the members is prevented, but when out of engagement longitudinal movement of said members is permitted, and a helical compressionspring connected at one end to said anvil member and at the other end said hammer member.

4. A rotary jar for use in well drilling comprising a rotary anvil cage, a rotary hammer telescopically mounted in said cage,

the hammer and anvilvhaving trip shoiilders, said shoulders being interrupted to perinit'the passage of the shoulders on the `hammer past the shoulders on the anvil and when said shoulders are in engagement fui'- ther longitudinal movement of the hammer and anvil is prevented but when out of engageinent longitudinal movement of said hammer and anvil is permitted, and a helical compression spring connected at one end to said anvil and at the other endto said hammer so varranged that closure of .said

anvil and hammer tends to turn them into 'JAMES ALLEN KAMMERDINER. 

